Although science has made significant progress to understand the ways in which Covid-19 behaves, there is still a lot of research to be done. With the arrival of the Omicron variant, the wave of contagions soared across the world.
According to the New York Times, those infected with the first Omicron variant are reporting second infections with the newer versions of the variant — BA.2 or BA2.12.1 in the United States, or BA.4 and BA.5 in South Africa. Alerts to keep an eye on the emergence of new variants remain latent.
It is currently difficult to know what the difference is between having Covid-19 or a common cold without a PCR or antigen test, so questions about the possibility of re-infection with coronaviruses or new variants are often asked by people around the world. Experts from the World Health Organization (WHO) have pointed out that until 2021, the risk of re-infection with Covid-19 was low.
The scenario then changed because of Omicron. Although millions of people have received immunization against the virus, new infections would occur because antibodies can be developed for one variant and not another. In January 2022, the United States reported a record 1.35 million new infections, the highest daily number of any country, according to Reuters data.
A report from Imperial College London on December 17, 2021, showed that Omicron has a strong ability to evade the immunity granted by a previous infection. The paper estimated that the risk of reinfection with Omicron is 5.4 times higher than with delta. Protection against reinfection with omicron provided by a past infection can be as low as 19%, the study indicates.
BBC reported that a study from MIT and Harvard University published in January 2022 showed that two doses of Pfizer or Moderna “do not produce antibodies capable of recognizing and neutralizing the Omicron variant” but that “a booster dose dramatically improves protection against omicron.” Andrew Lee, Professor of Public Health at the University of Sheffield, England, pointed out that data show that two doses of Pfizer or AstraZeneca vaccines offer limited protection against Omicron, but that protection is quickly restored with a booster dose. The vaccines are not designed to prevent infection, but to reduce the chances that someone who has been infected will develop a serious illness or die.
For now, it can be said that a person is at risk of re-infection if he or she has been previously infected with another variant. It has been noticed that the effects of the the Covid-19 vaccines will not be in the body forever.
Although everything indicates that Omicron may be less aggressive, the WHO has warned that it is necessary not to lower the guard. Earlier this year, Tedros Adhanom Ghebreyesus, director general of the world health body, said that “although Omicron appears to be less severe compared to delta, especially in those vaccinated, it does not mean that it should be classified as mild”.
According to several studies, more worrisome variants could follow Omicron and contagion is now considered a common occurrence. Experts believe that vaccination should be the main parameter to counteract the spread of the virus, as there is no exact figure specifying the number of times someone can become infected. The more time passes and the more the virus continues to mutate, the argument that re-infection will increase cannot be ruled out.